From the study “Accumulations of copper in apple orchard soils: distribution and availability in soil aggregate fractions“, of: Quan-Ying Wang, Jing-Shuang Liu, Yang Wang, and Hong-Wen Yu
The accumulations of Cu in aggregate size fractions of apple orchard soils due to the long-term application of Cu-based fungicides remain poorly understood.
Soil samples were collected from orchards with 10, 20, 31, 45, and 50 years old, and it was comproved that total soil Cu concentrations increased with increasing orchard ages. Generally, the Cu bioavailability and transferring capability have a tendency to increase with the increase of orchard age for both bulk soils and aggregate fractions.
The sizes of soil aggregate fractions can significantly influence the retention characteristics of input Cu in orchard soils.